Beneficial effects of direct foliar water uptake on shoot water potential of five chasmophytes

2003 ◽  
Vol 81 (12) ◽  
pp. 1278-1284 ◽  
Author(s):  
E Gouvra ◽  
G Grammatikopoulos
Keyword(s):  
Water Absorption ◽  
Water Potential ◽  
Water Movement ◽  
Water Shortage ◽  
Leaf Water ◽  
Beneficial Effects ◽  
Time Period ◽  
Leaf Surfaces ◽  
Foliar Water Uptake ◽  
Apoplastic Tracer

Five chasmophytic species growing as wall-fissure plants on vertical retaining walls of a castle in the town of Patras, Greece, were examined for their ability to benefit from direct absorption of foliar surface water. Epifluore scence microscopy and application of an apoplastic tracer of water movement indicated that sprayed water on leaf surfaces penetrated into the mesophyll of all species, and in some cases was also detected within conducting tissues of the leaf. Water potential (Ψw) of sprayed detached shoots was improved compared with unsprayed controls when they were slowly losing water under laboratory conditions. The beneficial effect of leaf water absorption on Ψw was found either on leaves that were originally fully turgid or on leaves that had undergone a considerable water content reduction. Sprayed leaves maintained their Ψw above turgor loss point for a time period of 10-90 min depending on species and degree of water deficiency. The relevance of the results to the importance of dew uptake from chasmophytes growing under water shortage in wall fissures in inhabited areas is discussed.Key words: chasmophytes, leaf water absorption, wall vegetation, drought resistance.

STEADY STATE RESISTANCE TO WATER FLOW IN CORN UNDER WELL WATERED CONDITIONS

1975 ◽  
Vol 55 (4) ◽  
pp. 941-948 ◽  
Author(s):  
P. A. DUBÉ ◽  
K. R. STEVENSON ◽  
G. W. THURTELL ◽  
H. H. NEUMANN
Keyword(s):  
Water Potential ◽  
Water Flow ◽  
Leaf Water Potential ◽  
Water Movement ◽  
Leaf Water ◽  
In Vivo Detection ◽  
Staining Techniques ◽  
Total Plant ◽  
Potential Gradients

Determinations of plant resistance to water flow from measurements of leaf water potential at steady transpiration rates were made on different lines of corn (Zea mays L.). Two inbreds, Q188, a wilting mutant, and DR1, an inbred line shown to have at least some heat and drought tolerance under field conditions, were compared to a commercial single-cross hybrid, United 106. The purpose of the experiment was to isolate the cause of the wilting characteristic of Q188. A linear relationship was found between leaf water potential and transpiration rate for all lines. No water potential gradients were found at zero transpiration. Low total plant resistances were observed in United 106 and DR1, with the major resistance being in the root system in both genotypes. Although the resistance to water movement through the roots and lower stalk in Q188 did not appear to differ from those of the other lines, a much larger resistance was found in the upper stalk of Q188; resistance to water movement through the lower stalk (up to node 5) decreased as the plants matured from 55 to 70 days of age but no comparable changes occurred in the upper portions of the stem. In vivo detection of the xylem vessels with staining techniques confirmed the observed differences in resistances.

Response of the components of sugar beet leaf water potential to a drying soil profile

1987 ◽  
Vol 109 (3) ◽  
pp. 437-444 ◽  
Author(s):  
Kay F. Brown ◽  
M. McGowan ◽  
M. J. Armstrong
Keyword(s):  
Sugar Beet ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Water Potential ◽  
Osmotic Potential ◽  
Seasonal Changes ◽  
Water Movement ◽  
Soil Water Potential ◽  
Leaf Water ◽  
Leaf Osmotic Potential

SummaryFor many field-grown crops, including sugar beet, there is little information on the seasonal changes in leaf water potential and its components as the soil dries. Therefore, seasonal changes in leaf water, osmotic and turgor potentials of sugar beet were measured in two seasons, in crops that experienced differing degrees of soil moisture stress. In 1983 potentials of crops exposed to early and late droughts were compared with those of irrigated crops, and in 1984 measurements were made in a non-irrigated crop. In the irrigated crop the midday leaf water potential changed little during the season, except in response to fluctuating evaporative demand. In the drought and non-irrigated treatments there was a sharp fall in leaf water potential as soon as the soil water potential decreased. The size of the midday leaf water potential was primarily determined by soil dryness. However, the leaf water potential did not decrease below about — 1·5 MPa in either year. The leaf osmotic potential declined at the same time as the leaf water potential, but the extent to which this happened differed in the two years. Only in the 1984 non-irrigated crop did the osmotic potential continue to decrease as the soil dried, suggesting that osmotic adjustment had taken place in 1984 but not in 1983. Thus higher turgor was maintained in the 1984 crop than in the 1983 drought-affected crops. Some turgors were recorded as apparently negative in 1983.Since the leaf water potential declined to a minimum of about — 1·5 MPa, the soil water potential minima were also about — 1·5 MPa. However, deeper soil was not dried to this extent, suggesting that the extra resistance for water uptake from deep soil was limiting or the rooting density was too low.The pattern of recovery of leaf water potential overnight suggested that the rhizosphere resistance to water movement was small, even as the soil dried. However, measurement of stem water potentials in 1984 indicated that a significant resistance to water flow existed within the aerial part of sugar beet plants. This shows that the use of the water potential in leaves as an estimate of that in stems or roots can be misleading.

Photosynthesis, transpiration, and leaf diffusive conductance of the cassava leaf in response to water stress

1983 ◽  
Vol 61 (1) ◽  
pp. 373-376 ◽  
Author(s):  
Jairo A. Palta
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Stomatal Closure ◽  
Net Photosynthesis ◽  
Water Shortage ◽  
Leaf Water ◽  
Manihot Esculenta Crantz ◽  
Water Potential Measurements ◽  
Response To Water ◽  
Made In

The effects of short periods of water shortage on the CO2 and water vapour exchange of attached cassava (Manihot esculenta Crantz 'M Col 72') leaves were measured. Gas-exchange and leaf water potential measurements were made in outdoor grown plants previously subjected to varying periods without water. Leaf water potentials fell to between −0.61 and −1.06 MPa and net photosynthesis and transpiration rates declined as leaf water potential decreased. Estimations of the leaf internal CO2 conductance indicated that the linear relationship established between leaf water potential and net photosynthesis is dominated by, but not completely explained by, stomatal closure.

The Effect of Water Shortage on Potted Peach Trees in Relation to Ecophysiological Parameters and Infra-red Thermometry

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541b-541
Author(s):  
Rita Giuliani ◽  
James A. Flore
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Early Detection ◽  
Water Potential ◽  
Canopy Temperature ◽  
Water Shortage ◽  
Development Rate ◽  
Plant Water ◽  
Infra Red ◽  
Peach Trees

Potted peach trees grown outdoors during the 1997 season were subjected to drought and subsequent rewatering to evaluate their dynamic response to soil water content. The investigation was primarily focused on the early detection of plant water stress to prevent negative effects on the growth. Leaf chlorophyll fluorescence and canopy temperature estimates (by infra-red thermometry) were conducted. Drought effect on physiological processes were detected through by estimates of canopy development rate, leaf gas-exchange measurements; while leaf water potential was measured to characterize plant water status. A decrease in the canopy's development rate was found 1 week after irrigation was stopped, which also coincided with a more-negative leaf water potential, whereas a decrease of the gas-exchange activities occurred several days later. No significant differences between the stressed and control plants were recorded by the chlorophyll fluorescence parameters (Fo, Fm, Fv and the ratio Fv/Fm), whereas the infra-red estimates of canopy temperature detected a slight increase of the canopy surface temperature (connected to the change of leaf energy balance and in relation to partial stomatal closure) on the non-irrigated plants 1 week after the beginning of the trial. The use of infra-red thermometry for early detection of water shortage is discussed.

Use of a Hydraulic Press for Estimation of Leaf Water Potential in Grain Sorghum 1

1986 ◽  
Vol 78 (4) ◽  
pp. 749-751 ◽  
Author(s):  
S. K. Hicks ◽  
R. J. Lascano ◽  
C. W. Wendt ◽  
A. B. Onken
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Grain Sorghum ◽  
Hydraulic Press ◽  
Leaf Water

Sampling Error for Leaf Water Potential Measurements in Wheat 1

Crop Science ◽  
1986 ◽  
Vol 26 (2) ◽  
pp. 380-383 ◽  
Author(s):  
R. C. Johnson ◽  
H. T. Nguyen ◽  
R. W. McNew ◽  
D. M. Ferris
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Sampling Error ◽  
Leaf Water ◽  
Water Potential Measurements

scholarly journals Microstructure and Durability Performance of Mortars with Volcanic Powder from Calbuco Volcano (Chile) after 4 Hardening Years

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1751
Author(s):  
Rosa María Tremiño ◽  
Teresa Real-Herraiz ◽  
Viviana Letelier ◽  
José Marcos Ortega
Keyword(s):  
Water Absorption ◽  
Thermal Analyses ◽  
Length Change ◽  
Cement Industry ◽  
Chloride Diffusion ◽  
Beneficial Effects ◽  
State Diffusion ◽  
Calbuco Volcano ◽  
Reference Specimens ◽  
The Impact

One of the most popular ways to lessen the impact of the cement industry on the environment consists of substituting clinker by additions. The service life required for real construction elements is generally long, so it would be interesting to obtain information about the effects of new additions after a hardening period of several years. Analyzed here are the effects of the incorporation of volcanic ashes, coming from Calbuco volcano’s last eruption (Chile), as clinker replacement, in the durability and pore structure of mortars, after approximately 4 hardening years (1500 days), in comparison with reference specimens without additions. The substitution percentages of clinker by volcanic powder studied were 10% and 20%. The microstructure was characterized with mercury intrusion porosimetry and impedance spectroscopy. In order to evaluate the pozzolanic activity of the volcanic powder after 1500 days, differential thermal analyses were performed. Water absorption after immersion, steady-state diffusion coefficient and length change were also studied. In accordance with the results obtained, the 10% and 20% substitution of clinker by volcanic powder from the Calbuco volcano showed beneficial effects in the mortars after 4 years, especially regarding the microstructure and chloride diffusion, without noticeable influence in their water absorption.

scholarly journals Terrestrial laser scanning intensity captures diurnal variation in leaf water potential

2021 ◽  
Vol 255 ◽  
pp. 112274
Author(s):  
S. Junttila ◽  
T. Hölttä ◽  
E. Puttonen ◽  
M. Katoh ◽  
M. Vastaranta ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Leaf Water
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